Hydrogen-rich syngas produced by catalytic steam gasification of corncob char

Abstract

Corncob char catalytic steam gasification for hydrogen-rich syngas was investigated using a lab-scale fixed bed gasifier to study the effects of temperature, steam flow rate, catalyst type and loading. The method of char absorbing catalyst was used to load catalyst in this work. Four alkali salts of KOH, K2CO3, NaOH and Na2CO3 were selected to pretreat corncob char. Results showed that hydroxides exhibited higher catalytic behavior. Further investigation on the effect caused by varying KOH concentrations to gasification performance has been done, and the maximum hydrogen yield of 197.8 g/kg char was obtained with 6 wt% concentration of KOH solution. Temperature and steam flow rate both has a positive influence on char conversion. Rising temperature promoted the hydrogen yield, and maximum hydrogen yield was obtained at 900 °C. With the steam flow rate increased from 0.2 g/min to 0.4 g/min, hydrogen yield increased by 84%, but a slight increase was found when steam flow rate further increased to 0.8 g/min.